Device for effecting heat interchange



Jan. 28; 1930. w, s, ow- 1,745,204

DEVICE FOR EFFECTING HEAT INTERCHANGE Filed April 11, 1924 Patented Jan.28, 1930 PATENT OFFICE WILLIAM SPENCER ,BOWEN,=OF JNEW .YORK, N. Y.

DEVICE FOR nrrno'rme HEKT INTERCHANGE Application filed April 11,

This invention relates to a device for effecting heat interchangebetween an explosive or combustible gaseous mixture and a fluid to beheated. The invention has for its foremost object the efficientgeneration of steam for power purposes but it is in no wise limited tothis or any other particular application of the principle of heattransfer.

Another object of the invention is the construction of a heater of theimmersion type in which the heat from the burning or exploded gas istransferred to the surrounding fluid by radiation as well as byconduction.

Still another object of the invention is the provision of means forabruptly changing the direction of flow of a heated gas or gases in aconduit whereby the conduit will be rendered radiant at the points ofabrupt change in I direction, by direct contact of the heated mediumWith the Walls of the conduit at these points.

A further object of the invention is the provision of a burner in whichthe incoming charge of combustible or explosive mixture is preheateddirectly by the heat of the previous charge as well as by thecounter-current flow of the hot exhaust products.

Other objects will appear as the descrip tion develops.

In the drawings Figure 1 is a section in elevation showing one form ofmy invention.

Figure 2 is a cross-section taken along the line 2-2 of Figure 1.

Referring to the drawings, and first to that form of the inventiondisclosed in Figures 1 and 2, the numeral 1 represents the wall of amixing chamber into which the ingredients of a combustible mixture areseparately admitted through the gas inlet 2 and the air inlet 3. Thecombustible mixture then passes into a flared combustion chamber t whichis preferably formed with a narrow neck or orifice 5 communicating withthe mixing chamber. A spark plug 6 is suitably arranged with theelectrodes thereof exposed within the combustion chamber. An exhaustconduit or tube 7 leads from the combustion chamber to any desired pointand preferably delivers the exhaust products to a turbine,

1924. Serial No. 705,919.

not'shown, or other source "of power production.

A boiler 8 surrounds the combustion chamber and that part of the exhaustconduit which lies a'dj acent thereto. "Said boiler has awater inlet 9and a steam outlet 10, the latter-leadingto any suitable engine or othersteam utilizing device. An annular shell or tube 11 is arranged withinthe boiler and spaced both from the wall of the boiler and the exhaustconduit and terminates to pro videa steam space-in the upper end of theboiler with its upper edge slightly above the water level of the boiler.Said shellisopen at the top, and at the bottom isprovided with ports 12.The object of the shell is to separate the contents of the'boiler intorelativelyhot inner and cold outer layers, the hot inner layer rising byconvection and flowing'over the top ofthe shell and the cold outer layerdescending by convection and flowing throughthe ports 12 to take theplace of the rising heated layer. The shell 11 preferably terminatesjust above the water level within the'boiler. To prevent the foam whichis due to ebullition of theheated layerfroln mixing with the steam-andbeing carriedout through the steam outlet-1O a foam deflector 13 isprovided which preferably closely surrounds the exhaust conduit andoverhangs the upper open-end ofthe shell 11 andthe concentric spacebetween the two shells.

A refractory deflector 1 1 is positionedwithin the exhaustpipe adjacentthe combustion chamber and in the zone of the shell 11,said deflectorcomprising a body formed with a spiral fin. The object of this deflectoris twofold. In the first place, it sets the exhaust gas whichflows pastit into a whirling motion which by centrifugalforce scours away theresidual layer of comparatively cool exhaust gas which lingers, due toskin friction, against the wall of the exhaust conduit. Thisgreatlyquickens the rate of heat interchange between the wall .of the 1 exhaustpipe and the layer of'water within the shell 11. Secondly the refractorydeflector becomes red hot andthcn radiates heat against the wall of theexhaust pipe, elevating the temperature of the latter and furtherincreasing the rate of heat interchange.

This embodiment of my invention can be operated in two ways, either by amerely combustible mixture or one of the proportions of which render itexplosive. Where the mixture is merely combustible, it burns continuallywithin the combustible chamber 4 after having once been ignited by thespark plug. In this instance the pressure of the ex aust product wouldbe comparatively low. When the mixture is explosive the refractorydeflector is heated by a succession of explosions. it being necessary inthis case to connect a timer, not shown, to the spark plug and fire themixture at regular intervals. When the explosion takes place theunburned portion of mixture is driven back temporarily through theorifice 5, a violent heat being imparted to the refractory deflector andthe exhaust products possessing considerable pressure and, therefore,power possibilities.

It is obvious that the specific details of construction andconfiguration of parts described herein may be modified in various wayswithout sacrificing the advantages of the invention or departing fromthe scope thereof as defined in the appended claims.

Having described my invention what I claim as new and desire to secureby Letters Patent, is

1. In a steam generator, a cylindrical outer boiler casing having aninlet and an outlet at opposite ends respectively, two telescopic tubesmounted concentrically of and within said casing and spaced apartadjacent the overlapping portions thereof, the inner tube forming theexhaust conduit, the outer tube being in communication at both ends withthe chamber formed by the inner tube and the casing and terminatingapproximately above the water level of the casing, a combustion chamberdisposed concentrically of the lower end of the outer tube and incommunication with and sealing the lower end of the inner telescopedtube, and a foam deflector mounted upon the inner tube above the upperend of the outer tube and overhanging the space between the inner andouter tubes.

2. In a steam generator, a cylindrical outor boiler casing having aninlet and an outlet at opposite ends respectively, two telescopic tubesmounted concentrically of and within said casing and spaced apartadjacent the overlapping portions thereof, the inner tube forming theexhaust conduit, the outer tube being in communication at both ends withthe chamber formed by the inner tube and the casing and terminatingapproximately above the water level of the casing, a combustion chamberdisposed concentrically of the lower end of the last tube and incommunication with and sealing the lower end of the inner telescopedtube, and an internal deflector WILLIAM SPENCER BOWEN.

